[PHOTOS] Behind the Scenes at the Museum: A Preview of SLAM's New Addition

The new galleries are, probably needless to say, state of the art. (That sort of thing is expected when you spend $130 million on a new building.) They'll be lit primarily by natural light, partially to save energy, partially to show the art the way it was meant to be seen.

Some of the light will come in through the windows -- which will bring Forest Park into the museum as well. The rest of it will come through 698 specially-designed concrete "coffers" in the ceiling. Each coffer contains a skylight, a light-diffuser and light fixtures to make up for times when natural light is not as strong as it could be. The balance between natural and artificial light will be maintained by sensors. When the museum is closed to the public, shades will go down over the windows and across the skylights to help preserve the art.

"There will be better color conditions when you look at the art," says Jeanette Fausz, the museum registrar. "Electric light adds color. When you see art in natural light, it brings a more honest look." It also means that the art will always look slightly different every time you come to the museum.

The challenge, though, is making sure that natural light doesn't fall directly on the paintings and fade the colors, and to make sure the climate is maintained at a precise 70 degrees with zero humidity.

The only things hanging on the wall now are thermometers, humidity readers and light meters at regular intervals throughout the galleries. The museum is conducting a thorough study of light and temperature conditions in order to determine where different pieces should go. Fausz estimates that the art will start coming in sometime in early 2013. The size of the new building will allow far more of the museum's holdings to go on display. At the moment, she estimates, 94 percent of the collection is in storage.

One piece is already in place: Andy Goldsworthy's sculpture Stone Sea, which occupies the courtyard between the two buildings. It's comprised of 25 arches carved from Missouri stone. You can get an aerial view of it now, from two of the galleries in the Gilbert building, but you'll be able to get closer once the new building opens in June.